Methods and Apparatus for Control Channel Detection in An Uplink Shared Channel

ABSTRACT

Methods and apparatus for channel detection in an uplink shared control channel. In an exemplary embodiment, a method includes generating soft-combined bit streams for an acknowledgement (ACK) indicator, rank indicator (RI), and channel quality indicator (CQI) received in an uplink shared channel. The method also includes decoding the ACK, RI, and CQI soft-combined bit streams to generate Top-M decoded bit streams for each indicator, and generating Top-Q symbols for each indicator from the Top-M decoded bit streams for each indicator. The method also includes calculating metrics from the Top-Q symbols and uplink control information (UCI) symbols extracted from the uplink shared channel, combining the metrics to form a search space, and searching the search space to determine transmitted ACK, RI, and CQI bits.

PRIORITY

This patent application is a continuation patent application of aco-pending U.S. patent application having a U.S. patent application Ser.No. 15/719,171, filed on Sep. 28, 2017 in the name of the same inventorand entitled “Methods and Apparatus for Control Channel Detection in AnUplink Shared Channel,” which is hereby incorporated herein by referencein its entirety.

FIELD

The exemplary embodiments of the present invention relate totelecommunications networks. More specifically, the exemplaryembodiments of the present invention relate to receiving and processingdata streams via a wireless communication network.

BACKGROUND

There is a rapidly growing trend toward mobile and remote data accessover high-speed communication networks, such as provided by thirdgeneration (3G) or fourth generation (4G) cellular services. Forexample, using these services, users now rely on their smartphones fortexting, access to email, banking, and social media, and for sending andreceiving pictures and video.

Typically, wireless network performance depends in part on the qualityof the transmission channel. For example, if the channel conditions aregood, the network may perform with higher speed and capacity than whenthe channel conditions are poor. To obtain the best network performance,wireless networks may rely on user devices (e.g., user equipment “UE”)to report control information back to the network. The controlinformation includes parameters indicating the channel conditions and/ortransmission parameters. One mechanism available to user devices toreport control information back to the network is through a physicaluplink shared control channel (PUSCH). The network receives the controlinformation over this channel and uses the received parameters to adjustdata transmissions for optimum performance based on the networkconditions indicated by the received parameters.

The PUSCH carries important uplink control information (UCI), includinga Channel Quality Indicator (CQI), a Rank Indicator (RI), and a HybridAutomatic Repeat Request Acknowledge (HARQ-ACK). The performance of ACKmessages play an important role in the overall downlink performance asthe residual error rate of HARQ is in the same order of the feedbackerror rate of the ACK bits. The CQI information represents therecommended modulation scheme and coding rate to be used for downlinktransmissions. Its accuracy greatly impacts the overall systemthroughput that can be achieved in a noisy channel. Thus, improving theerror performance of both CQI and ACK detection is desirable to theachieve improved network throughput.

However, there exists a tradeoff between allocating resources for thecontrol information and the resources reserved for data transmission.Typically, the more resources allocated to the control information, thebetter control information decoding performance. On the other hand, theresources allocated to the information are competing with the availableresource and achievable throughput for the uplink data. It is desirableto increase the decoding performance of the control bits withoutsacrificing the resource that can be allocated to the data portion. Yet,more advanced decoding should introduce minimum complexity and latency.

Therefore, it is desirable to have a detection mechanism thatefficiently detects with high probability, control bit informationtransmitted from user equipment over a PUSCH.

SUMMARY

In various exemplary embodiments, methods and apparatus are provided forcontrol channel detection in an uplink shared channel. For example, themethods and apparatus operate efficiently to detect with highprobability, control bit information transmitted from user equipmentover a PUSCH.

In an exemplary embodiment, a method is provided that includesgenerating soft-combined bit streams for an acknowledgement (ACK)indicator, rank indicator (RI), and channel quality indicator (CQI)received in an uplink shared channel. The method also includes decodingthe ACK, RI, and CQI soft-combined bit streams to generate Top-M decodedbit streams for each indicator, and generating Top-Q symbols for eachindicator from the Top-M decoded bit streams for each indicator. Themethod also includes calculating metrics from the Top-Q symbols anduplink control information (UCI) symbols extracted from the uplinkshared channel, combining the metrics to form a search space, andsearching the search space to determine transmitted ACK, RI, and CQIbits.

In an exemplary embodiment, an apparatus is provided that includes ademodulator that generates soft-combined bit streams for anacknowledgement (ACK) indicator, rank indicator (RI), and channelquality indicator (CQI) received in an uplink shared channel. Theapparatus also includes a decoder that decodes the ACK, RI, and CQIsoft-combined bit streams to generate Top-M decoded bit streams for eachindicator and a symbol generator that generates Top-Q symbols for eachindicator from the Top-M decoded bit streams for each indicator. Theapparatus also includes a metric calculator that calculates metrics fromthe Top-Q symbols and uplink control information (UCI) symbols extractedfrom the uplink shared channel, a combiner that combines the metrics toform a search space, and a joint detector that searches the search spaceto determine transmitted ACK, RI, and CQI bits.

Additional features and benefits of the exemplary embodiments of thepresent invention will become apparent from the detailed description,figures and claims set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary aspects of the present invention will be understood morefully from the detailed description given below and from theaccompanying drawings of various embodiments of the invention, which,however, should not be taken to limit the invention to the specificembodiments, but are for explanation and understanding only.

FIG. 1 shows a communication network comprising a transceiver having anexemplary embodiment of a control channel detector (CCD) thatefficiently receives and detects control bit information transmittedfrom user equipment over a physical uplink shared control channel;

FIG. 2 shows an exemplary embodiment of the control channel detectorshown in FIG. 1;

FIG. 3 shows exemplary embodiments of the baseband processor and thedemodulator/deinterleaver shown in FIG. 2;

FIG. 4 shows an exemplary embodiment of a resource grid;

FIG. 5 shows exemplary embodiments of the Top-M decoder and the Top-Qsymbol generator shown in FIG. 2;

FIG. 6 shows an exemplary embodiment of the joint detector shown in FIG.2; and

FIG. 7 shows an exemplary method for control channel detection in aphysical uplink shared control channel.

DETAILED DESCRIPTION

The purpose of the following detailed description is to provide anunderstanding of one or more embodiments of the present invention. Thoseof ordinary skills in the art will realize that the following detaileddescription is illustrative only and is not intended to be in any waylimiting. Other embodiments will readily suggest themselves to suchskilled persons having the benefit of this disclosure and/ordescription.

In the interest of clarity, not all of the routine features of theimplementations described herein are shown and described. It will, ofcourse, be understood that in the development of any such actualimplementation, numerous implementation-specific decisions may be madein order to achieve the developer's specific goals, such as compliancewith application and/or other constraints, and that these specific goalswill vary from one implementation to another and from one developer toanother. Moreover, it will be understood that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking of engineering for those of ordinary skills in the arthaving the benefit of embodiments of this disclosure.

Various embodiments of the present invention illustrated in the drawingsmay not be drawn to scale. Rather, the dimensions of the variousfeatures may be expanded or reduced for clarity. In addition, some ofthe drawings may be simplified for clarity. Thus, the drawings may notdepict all of the components of a given apparatus (e.g., device) ormethod. The same reference indicators will be used throughout thedrawings and the following detailed description to refer to the same orlike parts.

FIG. 1 shows a communication network 100 comprising a transceiver 116having an exemplary embodiment of a control channel detector (CCD) 118that efficiently receives and detects control bit informationtransmitted from user equipment over a physical uplink shared controlchannel. The network 100 may be configured as a third generation, fourthgeneration, long term evolution (LTE), or combination of 3G and 4Gcellular network.

The communication network 100 includes a server 114 that includes thetransceiver 116. The transceiver 116 has a transmitter portion 128 and areceiver portion 130. The server 114 communicates with a serving gateway(S-GW) 108 that further communicates with cell site 102 and the Internet112. The cell site 102 includes radio towers 110 and associated basestations (not shown).

User equipment (UE) 104 and user equipment 106 are in communication withbase station 110B. For example, the UEs 104, 106 can be cellular phones,handheld devices, tablet computers or iPad® devices. It should be notedthat the underlying concepts of the exemplary embodiments of the presentinvention would not change if one or more blocks (or devices) were addedor removed from the communication network 100.

In an exemplary embodiment, the UE 104 transmits control bit information124 to the server 114 using PUSCH 120 and the UE 106 transmits controlbit information 126 to the server 114 using PUSCH 122. In an exemplaryembodiment, the control bit information includes CQI bits, RI bits, andHARQ-ACK bits.

The receiver portion 130 includes receiver processing hardware (RPH)132. In an exemplary embodiment, the RPH 132 includes the CCD 118, whichis used to perform efficient detection of the control informationreceived over PUSCH from the user equipment. In various exemplaryembodiments, the CCD 118 is able to detect the control bit informationfrom received subframes with higher probability than conventionalsystems to enhance the overall efficiency of the receiver and theoperation of the communication network 100.

When control data are transmitted in the PUSCH, the control informationbits ACK, RI, CQI are encoded independently using different type ofencoding mechanisms depending on the number of information bits.Different coding rates for the control information are achieved byallocating a different number of coded symbols for its transmission.Specifically, when the number of ACK, RI or CQI bits is within the rangeas shown in Table 1, they are encoded with a Reed-Muller (32, O) codeand multiplexed with the turbo encoded data stream to form the PUSCHsignals.

TABLE 1 Control Info Number of Info Bits Encoder Encoded bits CQIO^(CQI) ≤ 11 RM (32, O) b₀ ^(CQI) b₁ ^(CQI), . . . , b₃₁ ^(CQI) ACKO^(ACK) ϵ [3, 11] RM (32, O) b₀ ^(ACK) b₁ ^(ACK), . . . , b₃₁ ^(ACK) RIO^(RI) ϵ [3, 11] RM (32, O) b₀ ^(RI) b₁ ^(RI), . . . , b₃₁ ^(RI)

In an exemplary embodiment, the transmitted ACK, RI and CQI informationbits are denoted as o^(ACK)=[o₀ ^(ACK) o₁ ^(ACK), . . . , o_(o) _(ACK)⁻¹ ^(ACK)], o^(RI)=[o₀ ^(RI) o₁ ^(RI), . . . , o_(o) _(RI) ⁻¹ ^(RI)],and o^(CQI)=[o₀ ^(CQI), o₁ ^(CQI), o₂ ^(CQI), o₃ ^(CQI), . . . , o_(o)_(CQI) ⁻¹ ^(CQI)], respectively, where O^(ACK), O^(RI), O^(CQI) are thenumber of information bits that falls into the range of Table 1,respectively. The control information bits are first coded using (32, O)block code, where the code words of the (32, O) block code are a linearcombination of 11 basis sequences denoted M_(i, n). The encodedACK/RI/CQI blocks are denoted by [b₀ ^(ACK/RI/CQI), b₁ ^(ACK/RI/CQI), b₂^(ACK/RI/CQI), b₃ ^(ACK/RI/CQI), . . . , b₃₁ ^(ACK/RI/CQI)], where

$b_{i}^{{{ACK}/{RI}}/{CQI}} = {\sum\limits_{n = 0}^{O^{{{ACK}/{RI}}/{CQI}} - 1}{( {o_{n}^{{{ACK}/{RI}}/{CQI}} \cdot M_{i,n}} ){mod}\; 2}}$

where i=0, 1, 2, . . . , 31. The output bit sequence will be circularlyrepeated to fit the number of resource elements and multiplexed with theturbo coded data stream for transmission.

FIG. 2 shows an exemplary embodiment of the control channel detector 118shown in FIG. 1. For example, the control channel detector 118 operatesto receive control bit information contained in a received PUSCH and todetermine the transmitted ACK, RI, and CQI bits.

In an exemplary embodiment, the control channel detector 118 uses atwo-stage processing architecture for processing the PUSCH to determinethe UCI. The first stage includes a preliminary Top-M survivalinformation bit decoder 208 for each control bit stream. The secondstage includes a joint ACK/CQI/RI detector 212 that uses amaximum-likelihood based metric search for survival candidates.

During operation, received RF signals 214 are received at an RF frontend 202. The received RF signals 214 comprise control bit informationtransmitted in a PUSCH. The front end passes the received RF signals 216to a baseband processor 204. For example, the baseband processor 204 ispart of the receiver 130 shown in FIG. 1. The baseband processor 204processes the received RF signals 214 to generate baseband signals 218.

A demodulator/deinterleaver 206 receives the baseband signals 218 outputfrom the baseband processor 204. The demodulator/deinterleaver 206operates to demodulate and deinterleave the baseband signals 218 togenerate UCI and data soft bits 220 that are output to a Top-M decoder208. The demodulator/deinterleaver 206 also outputs equalized timedomain symbols 224 to the joint detector 212.

A Top-M decoder 208 generates the Top-M candidates for each control bitstream, where M is a selectable integer value. Thus, the Top-M decoder208 generates the Top-M candidates for the ACK, RI, and CQI bits. TheTop-M candidates for the ACK/RI/CQI bits 222 including data bits areoutput to a Top-Q re-encode/symbol generator 210.

The Top-Q re-encode/symbol generator 210 receives the Top-M survival bitsequence candidates and independently re-encodes them using RM (32, O)encoders or using a LUT-based mechanism to generate coded-bits for eachcandidate information bit sequence. The coded-bits are used to generatesymbols 226 for each of the Top-Q candidates which are then output tothe joint detector 212.

The joint detector 212 generates a search space for all possiblecandidate symbols, which is searched to determine the most likely ACK228, RI 230, and CQI 232 bits.

Thus, the CCD 118 operates to generate a plurality of ACK/RI/CQIcandidates and converts these candidates into symbols. The symbols arecombined into a search space that is searched to determine the finalACK/RI/CQI bits. A detailed description of the CCD 118 is providedbelow.

FIG. 3 shows exemplary embodiments of the baseband processor 204 and thedemodulator/deinterleaver 206 shown in FIG. 2. In an exemplaryembodiment, the baseband processor 204 comprises time domain and FFTprocessors 302, resource demapper 304, and frequency domain processor306. The signals 216 output from the baseband processor 204 are outputto the demodulator/deinterleaver 206.

The demodulator/deinterleaver 206 comprises inverse DFT block (IDFT)308, demodulator 310, descrambler 312, soft combiners 314, 316, 318, andde-interleaver 320. In an exemplary embodiment, the receiver chaindesign up to the point of UCI extraction and soft-combining as well asthe turbo decoder for data portion can be the same as in a conventionalreceiver. In an exemplary embodiment, the equalized time-domain symbols224 output from the IDFT 308 in a subframe are denoted as

[r₀, r₁, …  , r_(l), …  , r_(N_(symb)^(PUSCH))],

where N_(symb) ^(PUSCH) is the number of OFDM symbols in a subframe.Assuming l is the symbol index within a subframe (including the DMRSsymbols where l={3,10} although it may not be required that these twosymbols to be processed by the IDFT 308). The demodulated LLRs outputfrom the demodulator 310 for either QPSK/16-QAM/64-QAM are denoted asfollows.

$\underset{\_}{\overset{\_}{}} = \begin{bmatrix}{\underset{\_}{}}_{0} & {\underset{\_}{}}_{1} & {\underset{\_}{}}_{2} & \ldots & {\underset{\_}{}}_{C_{\max} - 1} \\{\underset{\_}{}}_{C_{\max}} & {\underset{\_}{}}_{C_{\max} + 1} & {\underset{\_}{}}_{C_{\max} + 2} & \ldots & {\underset{\_}{}}_{{2C_{\max}} - 1} \\\vdots & \vdots & \vdots & \ddots & \vdots \\{\underset{\_}{}}_{{({R_{\max}^{\prime} - 1})} \times \; C_{\max}} & {\underset{\_}{}}_{{{({R_{\max}^{\prime} - 1})} \times \; C_{\max}} + 1} & {\underset{\_}{}}_{{{({R_{\max}^{\prime} - 1})} \times \; C_{\max}} + 2} & \ldots & {\underset{\_}{}}_{({{R_{\max}^{\prime} \times \; C_{\max}} - 1})}\end{bmatrix}$

Each resource element of the above matrix is a vector of (N_(L)*Q_(m))that carries the N_(L) layers of the Q_(m) LLR values for an individualresource element, where N_(L) is the number of layers, and the Q_(m) isthe modulation order that takes value from {2, 4, 6} for {QPSK, 16-QAM,64-QAM}, respectively.

Thus, from the system parameters {Q′_(ACK), Q′_(RI), Q′_(CQI)} and thechannel interleaver procedure, the UCI soft-bits can be readilyextracted from the resource grid shown in FIG. 4. In the resource grid,the locations of the different encoded-bits are marked with a shadingcode as shown in FIG. 4.

Referring again to FIG. 3, the extracted and soft-combined soft-bitsafter the CQI extraction and soft combining performed by combiner 314are denoted as {hacek over (q)}^(CQI)=[{hacek over (q)}₀ ^(CQI) {hacekover (q)}₁ ^(CQI), . . . , {hacek over (q)}₃₁ ^(CQI)], the soft-bitsafter ACK extraction and soft-combining performed by the combiner 318are denoted as {hacek over (q)}^(ACK)=[{hacek over (q)}₀ ^(ACK) {hacekover (q)}₁ ^(ACK), . . . , {hacek over (q)}₃₁ ^(ACK)] and the extractedand soft-combined RI soft-bits after soft-combining by the combiner 316are denoted as {hacek over (q)}^(RI)=[{hacek over (q)}₀ ^(RI){hacek over(q)}₁ ^(RI), . . . , {hacek over (q)}₃₁ ^(RI)]. The data channelde-interleaver 320 operates to de-interleave the data portion of theresource grid 400 to generate soft data bits.

FIG. 5 shows exemplary embodiments of the Top-M decoder 208 and theTop-Q symbol generator 210 shown in FIG. 2. In an exemplary embodiment,the Top-M decoder 208 comprises a Top-M CQI list decoder 502, a Top-M RIlist decoder 504, a Top-M ACK list decoder 506, and a data turbo decoder508.

As the decoding performance of both the control information and the datadirectly impacts the overall system throughput, better performancedetection is always desired. In conventional systems, a standalone RMdecoder works by itself to decode the ACK, RI and CQI bit streamsseparately with a sole decoded bit sequence. However, in variousexemplary embodiments, the Top-M decoder 208 utilizes a separate RMdecoder for each stream thereby improving decoding efficiency.

The Top-M CQI list decoder 502 generates the Top-M candidates (where Mis a selectable integer) of the CQI bits by using the {hacek over(q)}^(CQI) as an input to a RM (32,O) decoder that generates not onlythe decoded hard-bits CQI, but also the Top-M candidates ô_(j) _(CQI)^(CQI)=[ô₀ ^(CQI), ô₁ ^(CQI), ô₂ ^(CQI), ô₃ ^(CQI), . . . , ô_(O) _(CQI)⁻¹ ^(CQI)]_(j) _(CQI) that have the highest correlation result from theRM decoder. Similarly, the Top-M RI list decoder 504 and the Top-M ACKlist decoder 506 process the {hacek over (q)}^(RI) and {hacek over(q)}^(ACK) bit streams independently to generate the Top-M candidatesfor both RI and ACK bits, namely,

ô_(j_(RI))^(RI) = [ô₀^(RI)ô₁^(RI), …  , ô_(O^(RI) − 1)^(RI)]_(j_(RI))  andô_(j_(RI))^(ACK) = [ô₀^(ACK)ô₁^(ACK), …  , ô_(O^(ACK) − 1)^(ACK)]_(j_(ACK)),

respectively, where {j_(CQI), j_(ACK), j_(RI)}ϵ[0, M−1]. In anotherexample, {j_(CQI), j_(ACK), j_(RI)} can take different M values ifnecessary.

In an exemplary embodiment, the M survival bit sequence candidates willbe re-encoded using a RM (32,O) encoder or using a LUT-based mechanismto generate the coded-bits for each candidate information bit sequenceand then circularly repeated (for rate matching) as performed during thetransmission of the UCI bits to make M parallel bit-sequences outputfrom bit re-encode and rate matching circuits 510, 512, 514 as

${{\hat{\underset{\_}{q}}}_{j_{CQI}}^{CQI} = \lbrack {{\hat{q}}_{0}^{CQI},{\hat{q}}_{1}^{CQI},\ldots \mspace{14mu},{\hat{q}}_{{N_{L} \cdot Q_{CQI}} - 1}^{CQI}} \rbrack_{j_{CQI}}},{{\hat{\underset{\_}{q}}}_{j_{ACK}}^{ACK} = {\lbrack {{\hat{\underset{\_}{q}}}_{0}^{ACK},{\hat{\underset{\_}{q}}}_{1}^{ACK},\ldots \mspace{14mu},{\hat{\underset{\_}{q}}}_{Q_{ACK}^{\prime} - 1}^{ACK}} \rbrack_{j_{ACK}}\mspace{14mu} {and}}}$${{\hat{\underset{\_}{q}}}_{j_{RI}}^{RI} = \lbrack {{\hat{\underset{\_}{q}}}_{0}^{RI},{\hat{\underset{\_}{q}}}_{1}^{RI},\ldots \mspace{14mu},{\hat{\underset{\_}{q}}}_{Q_{RI}^{\prime} - 1}^{RI}} \rbrack_{j_{RI}}},$

where each sub-vector within the vector is of the size of (N_(L)*Q_(m)).

The Top-M possible CQI/ACK/RI candidates will be merged to produce M³possible candidate sequences. The re-encoded data bits {circumflex over(f)} after the turbo encoder and rate-matching circuit 516 aremultiplexed with the M-branches of CQI bits {circumflex over (q)}_(j)_(CQI) ^(CQI) by multiplexer 520 and then passed to the channelinterleaver 522. The interleaved bits will be scrambled by the scrambler524 using the same scrambler code used in the received transmission toproduce {circumflex over ({tilde over (b)})}_((j) _(ACK) _(,j) _(RI)_(,j) _(CQI) ₎=[{circumflex over ({tilde over (b)})}^((q))(0), . . . ,{circumflex over ({tilde over (b)})}^((q)) (M_(bit) ^((q))−1)]_((j)_(ACK) _(,j) _(RI) _(,j) _(CQI) ₎ re-generated scrambled bits for allthe candidates. These scrambled bits will be passed to the QAM modulator526 to produce the all the candidate (Top-Q) data symbols {circumflexover (d)}_((j) _(ACK) _(,j) _(RI) _(,j) _(CQI) ₎=[{circumflex over(d)}^((q))(0), . . . , {circumflex over (d)}^((q))(M_(symb)^((q))−1)]_((j) _(ACK) _(,j) _(RI) _(,j) _(CQI) ₎ for the M-candidatesof ACK/CQI/RI bits. The {circumflex over ({tilde over (b)})}_((j) _(ACK)_(,j) _(RI) _(,j) _(CQI) ₎ bits can also be written in the format asfollows to match the OFDM time-frequency resource grid, where eachcolumn vector represents a single OFDM symbol.

$\overset{\_}{\underset{\_}{\zeta}} = \begin{bmatrix}{\underset{\_}{\zeta}}_{({0,0})} & {\underset{\_}{\zeta}}_{({0,1})} & \; & \ldots & {\underset{\_}{\zeta}}_{({0,{N_{sym}^{PUSCH} - 1}})} \\{\underset{\_}{\zeta}}_{({1,0})} & {\underset{\_}{\zeta}}_{({1,1})} & \; & \ldots & {\underset{\_}{\zeta}}_{({1,{N_{sym}^{PUSCH} - 1}})} \\\vdots & \vdots & \vdots & \ddots & \vdots \\{\underset{\_}{\zeta}}_{({{N_{SC}^{PUSCH} - 1},0})} & {\underset{\_}{\zeta}}_{({{N_{SC}^{PUSCH} - 1},1})} & \; & \ldots & {\underset{\_}{\zeta}}_{({{N_{SC}^{PUSCH} - 1},{N_{sym}^{PUSCH} - 1}})}\end{bmatrix}$

In an exemplary embodiment, the candidate symbols can be formed into atime-frequency resource grid to match the resource allocation shown inFIG. 4.

FIG. 6 shows an exemplary embodiment of the joint detector 212 shown inFIG. 2. In an exemplary embodiment, the joint detector 212 comprisessymbol extractor 602, joint metric calculator 604, metric combiner 606,and joint detection circuit 608.

In an exemplary embodiment, symbol extractor 602 receives the symbolsoutput from the IDFT 308 and extracts only the UCI symbols and buffersthem to feed to the joint maximum-likelihood based metric calculator 604that receives the corresponding {circumflex over (d)}_((j) _(ACK) _(,j)_(RI) _(,j) _(CQI) ₎ resource elements. In an exemplary embodiment, thesymbol extractor 602 extracts a subset of equalized symbols denoted as{tilde over (r)}_((j) _(ACK) _(,j) _(RI) _(,j) _(CQI) ₎ that are asubset of the time domain symbols [r₀, r₁, . . . , r₁, . . . , r_(N)_(symb) ^(PUSCH)]. The operation of the extractor 602 to extract thesubset of equalized symbol can be expressed as the following.

${\overset{\sim}{r}}_{({j_{ACK},j_{RI},j_{CQI}})} = {{UCIExtract}( \lbrack {r_{0},r_{1},\ldots \mspace{14mu},r_{l},\ldots \mspace{14mu},r_{N_{symb}^{PUSCH}}} \rbrack )}$

In an exemplary embodiment, the joint metric calculator 604 computes amaximum-likelihood based metric jointly for the Top-M ACK, RI and CQIregenerated symbols. In an exemplary embodiment, the ML metric is afunction of the extracted time domain equalized symbols output from theIDFT 308 and expressed as follows.

Metric_(j) _(ACK) _(,j) _(RI) _(,j) _(CQI) ^(l,r) =f({circumflex over(d)} _((j) _(ACK) _(,j) _(RI) _(,j) _(CQI) ₎ ,{tilde over (r)} _(ACK)^(l,r) ,{tilde over (r)} _(ACK) ^(l,r) r _(RI) ^(l,r))

In an exemplary embodiment, the metric should possess good correlationcharacteristics to differentiate the candidates. Specifically, a desiredmetric will give a peak value for the right candidate (j_(ACK), j_(RI),j_(CQI)) that is transmitted but gives very small values for those wrongcombination of candidates. As shown above, the indices (l, r) denote theOFDM symbol index and the receive antenna index, respectively.

In an exemplary embodiment, the ML-metric combiner 606 is applied toachieve a diversity gain across multiple antennas and multiple symbolsas follows.

${Metric}_{j_{ACK},j_{RI},j_{CQI}}^{ALL} = {\sum\limits_{r}{\sum\limits_{l}{Metric}_{j_{ACK},j_{RI},j_{CQI}}^{l,r}}}$

The above only gives an example of one type of metric combining. Inanother embodiment, the combining can follow a different order where themetric itself is performed in multiple steps as follows.

${Metric}_{j_{ACK},j_{RI},j_{CQI}}^{r,{partial}} = {g( {{\hat{d}}_{j_{ACK},j_{RI},j_{CQI}},{{\overset{\sim}{r}}_{ACK}^{l,r}{\overset{\sim}{r}}_{CQI}^{l,r}},{\overset{\sim}{r}}_{RI}^{l,r}} )}$${Metric}_{j_{ACK},j_{RI},j_{CQI}}^{ALL} = {\sum\limits_{r}{Metric}_{j_{ACK},j_{RI},j_{CQI}}^{r,{partial}}}$

In an exemplary embodiment, the joint ACK/CQI/RI detector 608 searchesall the possible space of combined Top-M ACK, CQI and RI bit candidatesto determine the final bit sequences for ACK 610, RI 612, and CQI 614.Specifically, the final detected joint bit sequences for ACK, CQI and RIbits are determined by the following.

$\lbrack {{\hat{o}}^{ACK},{\hat{o}}^{CQI},{\hat{o}}^{RI}} \rbrack = {\underset{j_{ACK},j_{RI},j_{CQI}}{\arg \; \max}( {Metric}_{j_{ACK},j_{RI},j_{CQI}}^{ALL} )}$

FIG. 7 shows an exemplary method 700 for control channel detection in aphysical uplink shared control channel. For example, the method 700 issuitable for use with the CCD 118 shown in FIGS. 2-6.

Block 702 comprises an operation of receiving a shared control channeltransmission. For example, control channel transmission comprises ACK,RI and CQI bits received in a PUSCH. In an exemplary embodiment, thecontrol channel transmission is received by the RF front end 202 and thereceived information is passed to the baseband processor 204.

Block 704 comprises an operation of generating soft-combined bitsstreams for the ACK, RI, and CQI parameters. In an exemplary embodiment,the demodulator/deinterleaver 206 generates these soft-combined bitstreams along with soft data bits that are output to the Top-M decoder208.

Block 706 comprises an operation of separately decoding the ACK, RI, andCQI soft-combined bit streams to generate Top-M independently decodedbit streams. In an exemplary embodiment, the Top-M decoder 208 includesseparate RM decoders (502-506) that generates the Top-M candidate bitsstreams for each of the ACK, RI, and CQI information. The decoder 208also includes a data turbo decoder that generates hard data bits.

Block 708 comprises an operation of generating Top-Q symbols form theTop-M bit streams. For example, this operation is performed by the Top-Qsymbol generator 210. For example, in an exemplary embodiment, the Top-Mcandidate bits streams are re-encoded and rate matched by circuits(510-514). The rate matched data flows to channel interleaver 522, whichoutputs interleaved data to the scrambler 524. The scrambled output isthem modulated by the modulator 526 to generate the Top-Q symbols. In anexemplary embodiment, the above operations are performed substantiallythe same as in the transmitted that transmitted the received PUSCHtransmission.

Block 710 comprises an operation of extracting UCI symbols is performed.For example, in an exemplary embodiment, this operation is performed bythe UCI symbol extractor 602.

Block 712 comprises an operation of calculating a joint metric based onthe Top-M symbols and the extracted symbols. For example, this operationis performed by the metric calculator 604.

Block 714 comprises an operation of combining metrics to form a searchspace. For example, the metrics combiner 606 performs this operation.

Block 716 comprises an operation of searching the combined metric spaceto determine the final ACK, RI, and CQI bits. For example, the jointdetection circuit 608 performs this operation.

Thus, the method 700 operates to efficiently detect control bitsreceived in a PUSCH transmission. It should be note that the operationof the method 700 are exemplary and may be changed, modified, added to,delete from, and/or rearranged within the scope of the embodiments.

The exemplary aspect of the present invention includes variousprocessing steps as described above. The steps may be embodied inmachine or computer executable instructions. The instructions can beused to cause special purpose system, which is programmed with theinstructions, to perform the steps of the exemplary embodiment of thepresent invention. Alternatively, the steps of the exemplary embodimentof the present invention may be performed by specific hardwarecomponents that contain hard-wired logic for performing the steps, or byany combination of programmed computer components and custom hardwarecomponents.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from these exemplary embodiments and their broaderaspects. Therefore, the appended claims are intended to encompass withintheir scope all such changes and modifications as are within the truespirit and scope of these exemplary embodiments of the presentinvention.

What is claimed is:
 1. A method of obtaining control informationrelating to wireless communication channels for a communicationsnetwork, comprising: descrambling radio frequency (“RF”) signals from anuplink shared channel to generate a descrambled bit stream; forwarding afirst copy of the descrambled bit stream to a first control signalextraction and soft combiner for extracting soft bits relating tocontrol information from a time-frequency resource grid and combiningthe soft bits to produce a first soft bit stream representing a firstcontrol signal; and forwarding a second copy of the descrambled bitstream to a second control signal extraction and soft combiner forextracting soft bits relating to control information from thetime-frequency resource grid and combining the soft bits to produce asecond soft bit stream representing a second control signal.
 2. Themethod of claim 1, further comprising sending the first soft bit streamto a first control information decoder to decode the first soft bitstream to generate a first decoded bit stream.
 3. The method of claim 2,further comprising sending the second soft bit stream to a secondcontrol information decoder to decode the second soft bit stream togenerate a second decoded bit stream.
 4. The method of claim 3, furthercomprising sending the first decoded bit stream to a control signalencoder to encode the first decoded bit stream for generating a firsttop-M candidate relating to the first control signal.
 5. The method ofclaim 4, further comprising sending the second decoded bit stream to acontrol signal encoder to encode the second decoded bit stream forgenerating a second top-M candidate relating to the second controlsignal.
 6. The method of claim 5, further comprising generating aplurality of top-Q candidate symbols in response to the first top-Mcandidate and the second top-M candidate.
 7. The method of claim 6,further comprising generating a plurality of top-Q candidate symbols inresponse to the first top-M candidate and the second top-M candidate. 8.The method of claim 7, wherein generating a plurality of top-Q candidatesymbols includes identifying channel quality indicator (“CQI”) as afirst candidate and rank indicator (“RI”) as a second candidate.
 9. Themethod of claim 1, wherein forwarding a first copy of the descrambledbit stream to a first control signal extraction and soft combinerincludes: generating soft-combined bit streams for an acknowledgement(“ACK”) indicator; decoding the soft-combined bit streams to generateTop-M decoded bit streams for the ACK indicator; and generating Top-Qsymbols for the ACK indicator from a Top-M decoded bit streams for theACK indicator.
 10. The method of claim 9, wherein forwarding a firstcopy of the descrambled bit stream to a first control signal extractionand soft combiner includes: calculating metrics from the Top-Q symbolsand uplink control information (“UCI”) symbols extracted from the uplinkshared channel; combining the metrics to form a search space; andsearching the search space to determine transmitted channel indicatorsincluding ACK bits.
 11. The method of claim 9, wherein generating Top-Qsymbols for the ACK indicator includes: generating re-encoded and ratematched bits for the Top-M decoded bit streams for the ACK indicator;channel interleaving the re-encoded and rate matched bits to generateinterleaved bits; scrambling the interleaved bits to generate scrambledbits for each of the Top-M decoded bit streams for the ACK indicator;and modulating the scrambled bits to generate the Top-Q symbols for theACK indicator.
 12. The method of claim 1, wherein the uplink sharedchannel is a physical uplink shared control channel (PUSCH) in atelecommunication system.
 13. A network device configured to obtaincontrol information for wireless communication channels for acommunications network, comprising: a descrambler configured todescramble radio frequency (“RF”) signals from an uplink shared channelfor generating a descrambled bit stream; a first extraction and softcombiner coupled to the descrambler and configured to extract first softbits relating to a channel quality indicator (“CQI”) from atime-frequency resource grid and combine the first soft bits to producea first soft bit stream representing the CQI via the descrambled bitstream from the descrambler; a second extraction and soft combinercoupled to the descrambler and configured to extract second soft bitsrelating to an acknowledgement (“ACK”) from the time-frequency resourcegrid and combine the second soft bits to produce a second soft bitstream representing the ACK via the descrambled bit stream from thedescrambler; and a third extraction and soft combiner coupled to thedescrambler and configured to extract third soft bits relating to a rankindicator (“RI”) from the time-frequency resource grid and combine thethird soft bits to produce a third soft bit stream representing the RIvia the descrambled bit stream from the descrambler.
 14. The device ofclaim 13, further comprising: a first decoder coupled to the firstextraction and soft combiner and configured to decode the first soft bitstream to generate a decoded CQI bit stream; a second decoder coupled tothe second extraction and soft combiner and configured to decode thesecond soft bit stream to generate a decoded ACK bit stream; and a thirddecoder coupled to the first extraction and soft combiner and configuredto decode the third soft bit stream to generate a decoded RI bit stream.15. The device of claim 14, further comprising a Quadrature amplitudemodulation (“QAM”) modulator coupled to the first, second, and thirddecoders and configured to generate a plurality of top-Q candidatesymbols.
 16. The device of claim 15, further comprising a joint detectorcoupled to the QAM modulator and configured to generate a plurality ofbit sequences for ACK, CQI, and RI.
 17. A method of obtaining controlinformation relating to wireless communication channels for acommunications network, comprising: descrambling radio frequency (“RF”)signals from an uplink shared channel to generate a descrambled bitstream; extracting acknowledgement (“ACK”) bits from a time-frequencyresource grid by a first extraction and soft combiner via thedescrambled bit stream and combining the ACK bits to produce an ACK softbit stream; extracting channel quality indicator (“CQI”) bits from thetime-frequency resource grid by a second extraction and soft combinervia the descrambled bit stream and combining the CQI bits to produce anCQI soft bit stream; and extracting rank indicator (“RI”) bits from thetime-frequency resource grid by a third extraction and soft combiner viathe descrambled bit stream and combining the RI bits to produce a RIsoft bit stream.
 18. The method of claim 17, further comprising: sendingthe ACK soft bit stream to a first decoder for generating a decoded ACKbit stream; sending the CQI soft bit stream to a second decoder forgenerating a decoded CQI bit stream; and sending the RI soft bit streamto a third decoder for generating a decoded RI bit stream.
 19. Themethod of claim 18, further comprising creating a search space inaccordance with the decoded ACK bit stream, the decoded CQI bit stream,and the decoded RI bit stream to achieve a diversity gain acrossmultiple antennas and multiple symbols.
 20. The method of claim 19,further comprising performing a joint detection utilizing a maximumlikelihood (“ML”) metric to determine transmitted ACK, RI, and CQI bits.